


Expect the Unexpected

by jchlmwn



Category: SEVENTEEN (Band)
Genre: Alpha Kim Mingyu, Alpha/Beta/Omega Dynamics, Alternative Universe - AEV canon divergence, Bottom Jeon Wonwoo, Breeding Kink, Fluff and Smut, Knotting, M/M, Male Lactation, Mingyu is whipped, Mpreg, Omega Jeon Wonwoo, Pregnant Sex, Secret Relationship, Self-Indulgent, Spoken to lillupon and she’s fine with this dont come for me, Teacher-Student Relationship, Top Kim Mingyu
Language: English
Status: Completed
Published: 2021-03-14
Updated: 2021-03-14
Packaged: 2021-03-21 21:33:37
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,311
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/30028149
Author URL: https://archiveofourown.org/users/jchlmwn/pseuds/jchlmwn
Summary: In the months Mingyu has known Wonwoo, or should he say Mr Jeon, he has always felt an attraction towards him. Mingyu is also very much aware he is not the only person who looks at Mr Jeon and thinks this which, in theory, he can’t blame the other students (or even teachers) for.However, Mingyu is the only one whose unborn baby is currently growing inside Mr Jeon’s womb.
Relationships: Jeon Wonwoo/Kim Mingyu
Comments: 27
Kudos: 195





	Expect the Unexpected

**Author's Note:**

  * Inspired by [Achieving Escape Velocity](https://archiveofourown.org/works/28951476) by [lillupon](https://archiveofourown.org/users/lillupon/pseuds/lillupon). 



In the months Mingyu has known Wonwoo, or should he say Mr Jeon, he has always felt an attraction towards him. Mingyu is also very much aware he is not the only person who looks at Mr Jeon and thinks this which, in theory, he can’t blame the other students (or even teachers) for- it’s hard to not become besotted upon being on the receiving end of those cat like intense yet soft eyes.

However, Mingyu _is_ the only one whose unborn baby is currently growing inside Mr Jeon’s womb and, unsurprisingly, it has made keeping his inner alpha under control extremely challenging. Seeing Wonwoo waddle into their classroom -usually in a high necked jumper or shirt to hide the marks Mingyu has left from endless rounds of sex- 6 months pregnant belly being supported by his palm while the another is holding his teaching notes, looking like the very definition of sin. It does things to him.

Much to his displeasure, he’s noticed it does things to others too. Or at least that’s what his alpha tells him whenever anyone so much as looks in Wonwoo’s direction as of recent. But he knows this protectiveness is not merely unjustified paranoia, if the random alpha student who approached Wonwoo in the hallway one day and asked if either ‘he or his baby needed a daddy’ is anything to go by. Fortunately, Mingyu had been walking down that same hall and had witnessed the entire thing. It was slightly less fortunate that he got suspended for two days for knocking the bastard out the minute he smelt the distress in Wonwoo’s scent, but he doesn’t feel an ounce of regret about the incident.

“Dude what the hell, why the fuck are you growling?”

Seungcheol saying this brought him out of his stupor, briefly shaking his head before mumbling something about his rut being near.

“Whatever man, just tone it back before Mr Jeon comes in, you know how sensitive pregnant omegas are to shit like that”

Just as he says this the bell rings and, as per usual, Mr Jeon enters right on the dot.

The novelty of seeing Wonwoo looking so ethereal with his baby bump has yet to wear off. He can’t take his eyes off of him, gawking at the unearthly beauty of the being standing in front of the classroom. Mingyu knows he looks like a love struck puppy right now, but he can’t even bring himself to care.

After Mr Jeon organises the papers on his desk, he lifts his eyes to meet the students.

He slightly breathlessly starts, “Good morning, so today we’re continuing with-” Wonwoo’s eyes then meet Mingyu’s as he glances across the students, and Mingyu doesn’t miss how he instinctively puts his hand on his rounded belly upon meeting the eyes of the alpha whos child he’s carrying, “-u-um, yes, sorry, continuing with kinetic energy. As a quick reminder, do the two warm up questions on page 43….“

Mingyu smiles to himself, hearing in his head Wonwoo complaining about so called ‘pregnancy brain’ making it hard for him to stay focused. God, he’s so adorable.

Jun kicks him under the table, whispering not-so-quietly “bro, he’s pregnant with another mans baby, seriously, stop being a creep”

Theres a few snickers from his classmates, mingy blushing at being called out for his gawking.

Luckily, Mr Jeon appears to of been oblivious to the incident, seemingly having a dilemma about how much longer he’ll manage to stand before needing to sit down before his feet and back begin to ache. He decides against sitting for now, determination in his eyes about writing out an explanation for the class on the whiteboard.

He walks out from behind his desk, holding his notes in one hand and the marker in the other, silently beginning to jot down the equations.

Oh, god.

Mr Jeon’s whole body is now on display. His slightly thicker thighs, covered by a pair of navy slacks, leading up to his now full ass and widened hips, then dipping into the curve of his lower back.

And, of course, his baby bump. The one which he’s carrying Mingyu’s child in. Yes, Mingyu knows he fixates on that a lot, but he struggles to comprehend its real sometimes. Mr Jeon, the teacher he’s been lusting and fawning over, allowed Mingyu to knot _and_ breed him.

Even before Mr Jeon’s pregnancy, physics classes have always been hard for Mingyu to concentrate in whilst his favourite teacher was holding the lesson, but this takes the term a bit too literally.

Especially as he remembers lifting up Mr Jeon and fucking him against that very wall one time after school. Legs wrapped around Mingyus waist, head thrown back in ecstasy and shirt half unbuttoned as the alpha thrusted his cock repeatedly into wonwoo’s sopping entrance. He remembers the feel of the omega gripping onto his shoulders for dear life as Mingyu held up his thighs, barely able to contain his incoherent demands for the alpha to go harder, faster, and panting out between thrusts “i-inside, c-come inside....oh fuck, g-gyu-”

This memory has his trousers suddenly feeling tight. Well fuck, he’s getting hard now. That’s all he needs for his friends to officially know something is up.

He nervously and subtly glances around, praying to every deity that nobody can tell but, of course with his senses heightened by pregnancy and his omega’s fine tuning to his baby daddy’s scent, Wonwoo freezes at the spike in his Mingyu’s scent, arm hovering in the air and unmoving. Mr Jeon shakily exhales and tries to take a deep breath, attempting to ignore the arousal his alpha is emitting. However, the sudden headiness of the air makes it even harder for Wonwoo to support the increased weight on his feet, hand going on his lower back.

Mingyu immediately forgets about the issue in his underwear, eyebrows furrowing seeing the discomfort his om- Mr Jeon is feeling, arm raising and asking “Mr Jeon, are you okay? Do you need me to take you to the nurse?”

Wonwoo turns away from the whiteboard with a pink dust littered across his cheeks, inhales and states, “Yes I’m fine, Mingyu, I think I’m just needing to sit down for now. In the meantime, every just continue with textbook exercises and let me know if you need any help.”

Wonwoo tries to hide the pain he feels with each step he takes,not wanting to demonstrate weakness or him struggling to his students, even though they all have their heads down in concentration, hobbling back over to his desk and slowly managing to descend into his chair.

Every cell in mingyus body protests against not going up to help support the omega pregnant with their baby, but mingyu knows causing a scene would only stress Wonwoo out even more, which isn’t good for him or the baby.

The relief that floods Mr Jeon’s scent once he sits down and rests his hands on his bump marginally calms down his alpha, eyes drawn to the way the omega stretches his neck to relieve some of the pressure from being hunched forward from the increased weight on his abdomen.

The noise of other students turning pages and writing down answers has long faded into the background, Mingyu simply unable to focus on anything but Wonwoo. Sensing he’s being watched, Mr Jeons eyes draw to Mingyus, immediately blushing at the intense and captivating stare he’s getting from the alpha. Shyly maintaining eye contact, wonwoo slowly starts to caress and rub his stomach in slowly subtle motions - something he’s recently started doing to calm down the baby when he turns.

Mingyu smiles at him again, knowing the omega is going to be the best parent.

The alpha already spends half his time daydreaming about Mr Jeon and their baby; things like helping Wonwoo when attending birth classes and starting to buy clothes for their little pup. Oh and of course that doctors appointment with doctor Kim where the omega was a stuttering mess when enquiring about sex positions that were safe while pregnant.

Oh that was a fun, fun day.

The sleepless nights ahead and the idea of witnessing childbirth intimidates most people, but Mingyu just can’t wait to see the perfect little combination of him and the man he loves. He wants nothing more than to just hold and love and protect Wonwoo and their pup, both before and after the birth .

He practically jumps out of his seat in shock when the bell rings, signalling the end of class.

Fuck, did he really just spend a whole class not getting an ounce of work done and fantasising? “Get a grip Mingyu”, he chants to himself internally as he packs up his unopened jotter while his peers file out of the classroom.

But fate loves to throw reverse cards at Mingyu in times like these.

Wonwoo is trying to get up out of his chair to bid his students farewell, but he can’t support his body weight alone. The second Mingyu realises this all thoughts of social decency are abandoned and, in front of seungcheol and Jun as the only remaining students in the room, leans down and wraps his arm around Wonwoo’s waist and lower back, helping him up.

Wonwoo is dead stiff, and when Mingyu pulls back he seems the shock in his omegas eyes. He doesn’t even want to turn around to see his friends reactions.

He quickly scampers back to his desk, thoroughly embarrassed, throwing his bag over his shoulder, suddenly in a rush to go and dig himself in the nearest hole.

Seungcheol and Jun has already started walking, clearly gearing up to start launching a load of questions, when Mingyu then hears;

“Mingyu, would you mind if I had a quick word?”

He closes his eyes. Turning around and with a fake a disinterested look he can muster, let’s out a “Sure, Mr Jeon”

He tries not to think about how seungcheol and Jun closed the door after they exited.

He looks up to see Mr Jeon looking at him seriously, “that was way too risky Mingyu, I think seungcheol especially seems to of caught on to something”

Mingyu frustratedly replies, “I know, I know, but it’s hard to control my instincts seeing you pregnant and not being able to help you when you’re struggling, I’m trying-“

Wonwoo fiercely retorts, “You don’t think it’s hard for me too? I’m the one having to carry the baby, and he’s got his energy from you, always moving around and kicking and-“ the words die on his tongue upon feeling a body press against his back, the familiar warmth of his daddy calming down their pup and making Wonwoo sag back into his alphas chest.

Mingyu slots his head in the juncture of his neck, hands wrapping around to cradle Wonwoo’s bump, “I’m sorry sweetheart, I know you’re the one doing all the hard work, I just wish there was more I could do”

A contemplative silence follows, each basking in the moment of comfort they have in their lovers arms.

“She knows your scent. She gets excited when you’re around”, Mr Jeon softly mutters.

Mingyu teases, “Just the pup?”

“Shut up, if I never got excited by you I wouldn’t be pregnant” Mr Jeon states, missing the implications of his words.

Mingyu smirks, “oh, you mean that kind of excited. Well don’t worry the feelings mutual”

He can tell Wonwoo is smiling now, placing his hands on top of mingyus own where they rest on his abdomen protectively, “ _Oh_?”

Mingyus voice drops an octave when he answers, “You don’t understand how hard it is to not to hold and make love to you constantly, how could I not want to keep you filled and pregnant when you wear it so well?”

Wonwoo leans his head back over mingyus shoulder, moaning softly at his alphas words - giving Mingyu full access to his long, pale neck, and able to look down at his unborn child when he feels a slightly kick against his hand.

“We shouldn’t....I have a class starting in 20 minutes...”, seemingly trying to remind himself more than the alpha.

Mingyu continues mouthing at his neck, “I thought you said last night you were just covering a biology class for Mr Hong”

Wonwoo is already struggling to think about anything but the alphas dick being near his entrance, murmuring “....yes, yes, a class....”

“Well, if you need to give a practical demonstration about the reproduction process...”

This seems to snap Wonwoo out of his daze slightly, turning around and grinning into a kiss, “God, you’re such an alpha”

Mingyu smirks, “well you didn’t appear to mind when you were sat on my knot last night demanding a third round”

Wonwoo slaps his chest, going bright red, “don’t use my pregnancy libido against me-“, he teases his hand down his chest towards the front of Mingyus trousers, “besides, you don’t seem to mind....”

Mingyu groans, mind already venturing in territory it shouldn’t in a classroom during the school day.

He brings Mr Jeon to sit on his lap on the desk chair, his bulge growing as it slips past the rim of the omegas hole through their clothes.

Both of them moan as Wonwoo grinds into Mingyu crotch, back facing him and using the desk as support for his arms, arching his spine as he loses himself in arousal.

Mingyu brings his hands up from their place over Wonwoos rounded belly, briefly brushing over his nipples when Wonwoo shrieks.

“F-fuck, Mingyu, they’re sensitive right now-“

But something halts Mingyu in his tracks entirely.

What is that scent he’s picking up on? He can’t describe it as anything but absolutely _heavenly_. About to complain about his alpha stopping their ministrations, something seems to click in Wonwoos head about the confusion on his alphas face.

“Oh” he intelligently lets out.

Mingyu starts, “what is that scent coming fr— oh _fuck_ ”

He must be dreaming. There is no way this is real. Mr Jeon, his omega teacher, is sitting on his lap pregnant with his baby-

_Leaking milk_

This is the stuff of fantasies. If it’s not the hottest fucking thing Mingyu has ever seen in his life.

He practically pounces, lifting Mr Jeon up onto his desk and unbuttoning his shift, revealing his swollen nipples, dripping milkdown his chest.

All Wonwoo can get out is a panicked “Mingyu-“ before he dives down, fingers immediately gripping on the hair of the alpha who’s mouth is now lapping up the milk on his chest, eventually reaching the source and beginning to suck the liquid gold Wonwoo leaking from his hardened and puffy tits.

Wonwoo trembles, looking down and brushing his hands through the alphas mess of hair. “f-fuck, you don’t have t-ah-to do this...”

Mingyu only sucks harder, making Wonwoo moan, he pulls away licking his lips to bring his mouth up to Wonwoo’s ear, “You’re slowly killing me, Mr Jeon...” he brings his fingers to touch and squeeze at the glistening buds, “youre such a good omega, already producing milk for our pup, and in the meantime-“ he lifts a finger and licks a pearl drop of milk off his thumb “it’s all mine”

Wonwoo absolutely preens at the praise from his alpha, the change in his demeanour clear as day, switching from embarrassed to shyly proud in the span of a few seconds.

“So you’ll give me more pups?” he hopefully mumbles, clearly in a submissive and arousal-hazed state.

Yeah, Mingyu is definitely not going to survive at this rate.

—————————————

_One week later_

Mingyu lifts Mr Jeon up onto the desk and slots between his long legs, smashing their lips together, the omega moaning and squirming.

“Do you like me lifting you up? Want me to hold you down and fuck another pup into you? I’ll keep you on my knot so you’re stuffed full of my cock and seed, always getting pregnant and leaking milk”

Mr Jeon trembles, “Mingyu, please, fuck-”

Mingyu rips the offending shirt and trousers off the omega, leaving him completely bare on his desk. Mingyu only unzips his trousers, taking out his rock hard dick, twitching at the sight of the omega rounded with their pup and his leaking entrance and tits.

“ _Mingyu_ , please, I need your knot-“

Not wasting another second the alpha plunges his huge cock into Mr Jeons awaiting hole, already stretched from Wonwoo riding him six ways to sunday earlier, the omega moaning so loud that Mingyu has to lean down and start kissing him to quieten down, careful not to press on his enlarged stomach.

Mingyu immediately starts thrusting, seeing the omegas hole sucking him in so eagerly, tears streaming down Mr Jeons face in pleasure.

“F-fuck, oh _fuck_ , Mingyu, please don’t stop-“

Mingyu then turns Wonwoo around and bends him over the desk (or just his chest as he can’t lean on the baby), leaning his chest over Wonwoo’s back and entering again in one smooth thrust, holding his bump and locking his fingers with one of wonwoo’s hand supporting him of the desk, growling into his ear “Going to make sure everyone knows I got you pregnant, I knotted you and bred you, that my pup is in your womb and nobody else’s, that you’re _mine_ ”

Mr Jeon starts thrusting back to meet the alphas cock, breathing out profanities about going faster and getting him pregnant again and again between thrusts.

“Alpha, your knot, need it to keep me full of your pups, want to be your good omega...”

Mingyu only thrusts a few more times before his swollen knot catches on the rim of the omega, locking them together as mingyus hot seed floods into Mr Jeons awaiting cervix.

It was at this exact moment seungcheol opened the door out of curiosity upon hearing some peculiar noises in his physics classroom so late, and then the following sight greeted him:

His pregnant teacher, naked and leaking milk all over his baby bump, half bent over his desk, head fallen back into the shoulders of none other than Mingyu, who is behind him and, evidently knotted into him, holding and caressing his belly as his turned head is met with Mr Jeon’s in a deep passionate kiss. Still unaware that a student is about to have heart failure from shock, he breaks the kiss and puts his hands over mingyus on his naked stomach, “fuck, Mingyu, you breed me so well, you’re such a good alpha, going to be such a good daddy to our pup”

A disbelieving ”what the fuck” is all seungcheol can get out.

Mr Jeon positively shrieks, immediately trying to back away and cover himself, forgetting he is still attached to mingyus cock, and the movement only ends up making them both moan, but in mortification.

Mingyu starts, still standing behind and inside Wonwoo who has managed to find a shirt and haphazardly slip it over his naked torso “Seungcheol, look, I can explain-“

“You’re the father of Mr Jeon’s child? You two have had sex, fuck that, _are_ having sex?”

“Can we have this conversation in a minute? He’s pregnant and I, um, I’m kno-“

Wonwoo seethes, “Kim Mingyu if you don’t shut up right this second I swear to god”

Seungcheol stammers our incoherent excuses, seemingly about to run, when mingyus knot finally deflates enough for wonwoo’s hole to release him, although this means when Wonwoo stands up to reach for his trousers, a river of cum flows down his legs.

Seungcheol holds his breathe at the sudden stench of just Mingyu and arousal fill the air as his come leaks out their teacher.

“Oh, m-my god, I-can’t, uh, bye” is all seungcheol can muster before bolting.

Mingyu and Mr Jeon turn to each other, mentally screaming _fuck._

**Author's Note:**

> *clears throat* Uh, h-hi....I’ve never written before so I’m a little (read:very) nervous about this. It’s completely based off lillupon’s masterpiece Achieving Escape velocity, please go check that out if you haven’t already! This particular canon divergence is a one off/ stand alone, but I am in the works of writing the sequel to AEV! I hope you enjoyed this, I know it’s a mess and it’s probably filled with loads of errors, but I just needed a pregnancy episode with AEV minwon so...yeah. 
> 
> Oh a quick side note, everything with seungcheol ends up being fine, guy was just a little shell shocked but its sufficiently awkward between Mr Jeon and Seungcheol after that lmao


End file.
